By Quynh Le BBC Vietnamese service

Mai Thanh Hai, the 32-year-old son of Vice Minister of Trade Mai Van Dau, is alleged to have received 510m Vietnam dong ($32,000) in mid-2003 from a textile company owned jointly by US, South Korean and Vietnamese business interests.

As Vietnam's second largest export earner, the textile sector is expected to bring in $3.8bn in 2004, mostly due to exports to the US.

However this month has seen the industry slump to almost crisis-point, after the arrests of many officials in charge of quota allocations.

The Tuoi Tre newspaper said the company concerned had agreed to pay Mai Thanh Hai through an intermediary.

Mr Hai worked at the trade ministry's import-export department, in charge of garment quotas for the US.

Despite Mr Hai's intervention, the company only received half of its desired quota, and thus demanded its money back.

In August 2003, Mr Hai returned all the money to ensure no criminal complaint was filed against him.

It is not yet clear why this case has been uncovered now, but earlier this month Le Van Thang, the deputy director of the same import-export department, was arrested together with other officials over allegations of embezzlement.

The men were accused of forming a corruption ring, forcing Vietnamese garment and textile exporters to pay bribes to secure export quotas.

So far nine individuals implicated in the case have been arrested.

On Thursday, local residents and reporters surrounded Mr Hai's house to watch his arrest, an indication of the great interest the case has generated in Vietnam.

In a recent interview with the Phap Luat newspaper in Ho Chi Minh City, the Vice Minister of Trade, Mai Van Dau, was asked about rumours of his son receiving favours because of his own position.

The minister was quoted as saying: "A son has his own business, and so does the father. Even if he has something to ask me, I cannot disclose anything of the work at the ministry."